The advantages of air-filled thin plastic envelopes, cushions, and pillows or the lie for shipping, storing and otherwise protecting delicate articles placed therewithin, are explained in said prior patents and are now coming to be more appreciated for their improved efficacy, simplicity, lower cost, environmentally more desirable properties, and, where desired, re-visibility features, largely absent in the myriad of today's shipping materials and techniques.
The plastic sheet blanks for sealing and air-filling that are described in said patents comprise a pair of adjacent upper and lower flat plastic sheets ultimately forming the cushioning pillows when air inflated and peripherally sealed. They are constructed with parallel tilling inlet paths on each side of a central axis about which the pillows are folded with the article-to-be-protected inserted therebetween prior to inflation.
While the construction and manufacturing techniques disclosed in said patents have been found to work well in practice, higher speed commercial production and greater flexibility needs have given rise to the need for the improved techniques of the present invention. The operation of the machinery described in above-mentioned U.S. Pat. No. 5,651,237, involves first advancing the plastic substrate, such as that described in said U.S. Pat. No. 5,454,642, to a loading position, then placing an object-to-be-packaged on the film at the machine platform location, further holding the film over the object, heat-sealing the film around the object, inflating the air chambers of the package, and then removing the completed package from the machinery. Among these is the desirability for greater and even independent control (where desired) of the air injection into the above-discussed separate inlet paths, and other manufacturing refinements.